Eyeglass lens processing apparatus

Abstract

An eyeglass lens processing apparatus includes a processing control unit (50) which in the soft processing mode, roughs the lens such that the torque threshold value is set to a value Tθs lower than the threshold value TθN of a normal processing mode, and when torque detected by a sensor unit does not exceed the threshold value Tθs, a axis-to-axis distance varying unit or a lens rotating unit is controlled so that a cutting amount per rotation of the lens reaches a threshold cutting amount, and when the detected torque exceeds the threshold value Tθs, the axis-to-axis distance varying unit or the lens rotating unit is controlled so that the torque becomes lower than the threshold value Tθs to decrease the threshold cutting amount.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to an eyeglass lens processing apparatus for processing a periphery of an eyeglass lens.[0002]In eyeglass lens processing apparatuses used by an optician, a mainly used apparatus is that in which while an eyeglass lens held by a lens chuck shaft is rotated, an axis-to-axis distance between a grindstone spindle attached with roughing grindstone and the lens chuck shaft is changed based on target lens shape data, and the periphery of the lens is roughened by the roughing grindstone. In roughing a plastic lens by the roughing grindstone, a down-cut system in which a rotating direction of roughing grindstone 166 and that of an eyeglass lens LE are set opposite to each other, as shown in FIG. 1A, is adopted. The reason for this is that when an up-cut system in which the rotating direction of the roughing grindstone 166 and that of the lens LE are the same is adopted, as shown in FIG. 1B, if the lens LE is deeply cut by the ro...

AI Technical Summary

Benefits of technology

[0007]An object of the present invention is to provide an eyeglass lens processing apparatus, capable of reducing generation of an axial deviation of a lens while reducing generation of a large processing sound at the time of roughing.

Problems solved by technology

However, recently, there is a water-repellent lens of which the lens surface is coated with a water-repellent substance to which water, or oil, etc., does not easily adhere.

However, in the down-cut system, there is a problem in that a processing sound is larger at the time of roughing as compared to the up-cut method.

However, there is no example in which the effect is actually provided.

When the up-cut system is adopted, the problem of the aforementioned axial deviation is present even in a normal lens, and in the water-repellent lens, the problem of the axial deviation becomes even more conspicuous.

Thus, controlling of a change of the axis-to-axis distance or the lens rotation speed is difficult, and therefore, its application is difficult.

Even when the lens thickness is measured, accurate measurement of the lens thickness is not easy, and in an astigmatic lens, the lens thickness differs depending on each radial angle, and thus, it is even more difficult to know the lens thickness over the entire lens.

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